diff --git a/lib/modules/blockchain_process/simulator.js b/lib/modules/blockchain_process/simulator.js
index ab415968..4bb0ade6 100644
--- a/lib/modules/blockchain_process/simulator.js
+++ b/lib/modules/blockchain_process/simulator.js
@@ -30,7 +30,7 @@ class Simulator {
     let useProxy = this.blockchainConfig.proxy || false;
     let host = (dockerHostSwap(options.host || this.blockchainConfig.rpcHost) || defaultHost);
     let port = (options.port || this.blockchainConfig.rpcPort || 8545);
-    port = parseInt(port) + (useProxy ? constants.blockchain.servicePortOnProxy : 0);
+    port = parseInt(port, 10) + (useProxy ? constants.blockchain.servicePortOnProxy : 0);
 
     cmds.push("-p " + port);
     cmds.push("-h " + host);